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R&S FSH
Distance-to-Fault Mode (R&S FSH-K41)
Configuring Cable and Antenna Tests
Operating Manual 1309.6275.12 - 14
158
5.2.2 Configuring the Horizontal Axis
The FREQ key contains all necessary functions to define frequency and distance
parameters when performing cable measurements.
The contents of the menu depend on the currently selected measurement.
5.2.2.1 Setting the Frequency Range for DTF Measurements
In the default setting, the R&S FSH automatically selects a center frequency of
1.8 GHz (R&S FSH4) or 4 GHz (R&S FSH8) and a distance of 20 m. The R&S FSH
optimizes the settings for the best resolution, if you change the cable length.
If you have to keep the current frequency settings, it is best to define a manual span.
Setting the frequency span
When setting the frequency range, it is best to first set the span and then the center
frequency.
M
Press the SPAN key.
M
Press the "Manual Span" softkey.
By default, the R&S FSH automatically calculates the best span ("Auto Span") for
the best length resolution. If the required span is too large for the current center
frequency, the R&S FSH sets the center frequency to the smallest possible
frequency.
M
Enter the span you need manually.
The R&S FSH sets the new span. Note that the maximum span you can set
depends on the maximum cable distance you have defined and is never greater
than the span calculated by the "Auto Span" function. The minimum span that you
can set is 10 MHz.
Setting the displayed frequency range
After you have selected the span, you can set a particular frequency range whose
results the R&S FSH displays.
In the default configuration, the R&S FSH adjusts the DTF start and DTF stop
frequency according to the span and the center frequency. The distance from center
frequency to the start and stop frequency is the same. Alternatively, you can directly
set a DTF start and DTF stop frequency.
M
Press the FREQ key.
M
Press the "Center Freq" softkey.
M
Enter the frequency that you'd like to be in the center of the horizontal axis.
The R&S FSH adjusts the frequency range according to span and center
frequency.
M
Press the FREQ key.